  body {
    margin: 0 auto;
    display: flex;
    place-items: center;
    background-color: #c1c1c134;
    background-repeat: no-repeat;
    background-size: cover;
  }
 

  #app {
    margin: 0 auto;
    display: flex;
    width: 100%;
    height: 100vh;
    justify-content: center; /* 水平居中 */
    align-items: center; /* 垂直居中 */
  }


  * {
    user-select: none;
  }
  